What’s with all this presidential nastiness? Donald Trump issues scalding tweets about Gold Star families, Congressional Democrats and Republicans – even the NFL. It all reveals a person given to volatile and aggressive emissions of rhetoric. What sort of personality would produce such behavior in the Oval Office?

Psychologist Dan McAdams describes Trump thusly: “Across his lifetime, Donald Trump has exhibited a trait profile that you would not expect of a U.S. president: sky-high extroversion combined with off-the-chart low agreeableness.”

An individual’s personality is an OCEAN. That’s an acronym for the “five factor personality model” that is widely used in psychology. In this theory, people are characterized by their personal manifestations of the traits of (O) openness to experience, (C) conscientiousness, (E) extraversion, (A) agreeableness and (N) neuroticism.

Those open to experience are original creative, intellectual and have wide interests in contrast to those with commonplace, simple and conforming habits.

Important personality aspects

Conscientious people are thorough, dependable, precise and hardworking, unlike those who are lazy, careless, distractible and irresponsible.

Extraverted people are energetic, talkative, assertive and outspoken as opposed to those who are low key, reserved and shy.

Agreeable people are trusting, moderate and considerate, unlike those who are stubborn, ruthless, demanding and uncooperative.

Neurotic people are moody, tense, self-conscious and have trouble controlling their impulses in contrast to clam, relaxed and secure individuals.

A Disagreeable Extrovert

Trump is a disagreeable extrovert. What motivates this hot-blooded combination? According to McAdams, anger: “Anger can fuel malice, but it can also motivate social dominance, stoking a desire to win the adoration of others. Combined with a considerable gift for humor (which may also be aggressive), anger lies at the heart of Trump’s charisma. And anger permeates his political rhetoric.”

Add to that a president with low openness to new experiences. At 71, he’s set in his ways.

Trump’s traits closely resemble those of “dominator” presidents, so classified by Steven Rubenzer and Thomas Faschingbauer in their landmark study of presidential personality, Personality, Character and Leadership in the White House.

The dominators of presidential history were Andrew Jackson, Lyndon Johnson and Richard Nixon, described by the authors as “exceptionally bossy, demanding, domineering, manipulative; none was even tempered. All acted assertively, were self-centered and egotistical, stubborn and hardheaded and thought highly of themselves.”

Andrew Jackson, a ”dominator” as President.

Trump seems to share many of these traits. He has installed a portrait of Andrew Jackson, whom he admires, in the White House.

Trump’s dominator predecessors all ranked low on personal character, high in neuroticism and very low on openness and agreeableness. Since Trump shares these traits, his presidency is likely to continue to be a jarring ride.

Trump’s aggressiveness and frequent tweets have produced almost daily controversies over the truthfulness of his assertions. The media challenges many of his statements as factually untruthful. The Washington Post’s fact checking has identified over one hundred instances of “false and misleading claims” during his first six months in office. Many of his tweets – limited to 140 characters – understandably “lack context.”

Bravado in Business

Trump’s embellishments of the factual record have long been part of his approach in business. In The Art of the Deal he described it this way: “The final key to the way I promote is bravado. I play to people’s fantasies. People may not always think big themselves, but they can still get very excited by those who do. That’s why a little hyperbole never hurts. People want to believe that something is the biggest and the greatest and the most spectacular. I call it truthful hyperbole. It’s an innocent form of exaggeration—and a very effective form of promotion.”

Given the nation’s polarized politics, not everyone views Trump’s exaggerations as innocent. The low agreeableness and character of the dominator are evident in such behavior, indicating a jarring path for Donald Trump – and us – during his presidency. What to do? As Betty Davis, in the role of Broadway star Margo Channing, declared in the classic film All About Eve: “Fasten your seat belts. It’s going to be a bumpy night.”